Amniotic Fluid and the Fetal Mucosal Immune System

Amniotic fluid is frequently sampled by amniocentesis for genetic analysis of the fetus between 10. weeks and the end of the first half of pregnancy. Amniotic fluid plays a role in defense of the fetal and uterine structures against infection, signaling the uterus that the fetus has sustained an infection, initiating parturition, and/or modulating the maternal immune response to prevent rejection of the fetus. The number of potential sites for secretion of various constituents into the amniotic fluid is expanded after organogenesis. The cytokines and prostaglandins in the amniotic fluid might impact the development of the immune system of the fetus. Some antiretroviral drugs are able to cross the placenta and are concentrated in the amniotic fluid. This chapter summarizes immune factors that participate in the innate immune system during pregnancy.